Preheat the oven to 175°C and line two 25cm round, springform baking tins with compostable baking paper.
Add sugar and butter to a large bowl and mix with an electric mixer, until well combined and fluffy. Add the vanilla, eggs and yoghurt and mix on low speed until just combined.
In a separate bowl, mix all the dry ingredients. Add the dry ingredients to the wet ingredients and combine well.
Divide the mixture between the baking tins and bake for 40 minutes or until golden brown. Let the cakes completely cool before icing.
To make the icing
Mix the saffron and ground rose petals with hot water. Set aside.
Whip the cream and icing sugar. Once the mixture thickens, add the saffron and rose petal mixture and continue whipping until medium peaks form.
Spread half of the whipped cream over the top of one of the bases, then flip the second base over it so that the top part faces the cream layer. Spread the remaining cream over the top and sides of the cake and sprinkle the top with pistachios, rose petals and orange zest.
